unity实现贪吃蛇游戏

using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class SnackBody
{
  public SnackBody front; //表示 前一段蛇身
  public Transform self; //表示 当前蛇身
  Vector3 oldPos; //当前蛇身的前一个位置

  public SnackBody(SnackBody tmpFront, Transform tmpSelf)
  {
    front = tmpFront;
    self = tmpSelf;
    oldPos = tmpSelf.position;
  }

  //这一节蛇身已经向前移动了，更新oldPos
  public void Reflash()
  {
    oldPos = this.self.position;
  }

  //跟着前面的蛇身
  public void FollowFront()
  {
    self.position = front.oldPos; //更新蛇身的位置
    front.Reflash(); 
  }
  
  public virtual void MoveForward(){}
  }

public class SnackHead : SnackBody
{
  //继承基类
  public SnackHead(SnackBody tmpFront,Transform tmpSelf):base(tmpFront,tmpSelf) 
  {
  }
  public override void MoveForward()
  {
    self.Translate(-self.forward, Space.World);
  }

  /// <summary>
  /// 向右移动
  /// </summary>
  public void TurnRight()
  {
    Vector3 tmpAngle = self.localEulerAngles;
    tmpAngle.y += 90;
    self.localEulerAngles = tmpAngle;
  }

  /// <summary>
  /// 向左移动
  /// </summary>
  public void TurnLeft()
  {
    Vector3 tmpAngle = self.localEulerAngles;
    tmpAngle.y -= 90;
    self.localEulerAngles = tmpAngle;
  }
}

using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class SnackController : MonoBehaviour {

  List<SnackBody> allBodys; //存储所有的蛇身

  public Transform snackHead;
  public Transform bodyOne;
  public Transform bodyTwo;

  // Use this for initialization
  void Start () {

    allBodys = new List<SnackBody>();

    SnackHead tmpHead = new SnackHead(null, snackHead);
    allBodys.Add(tmpHead);

    SnackBody tmpOneBody = new SnackBody(tmpHead, bodyOne);
    allBodys.Add(tmpOneBody);

    SnackBody tmpTwoBody = new SnackBody(tmpOneBody, bodyTwo);
    allBodys.Add(tmpTwoBody);

    StartCoroutine(MoveFront());
  }

  IEnumerator MoveFront()
  {
    while(true) //用一个死循环来让蛇一直移动
    {
      allBodys[0].MoveForward();

      yield return new WaitForSeconds(0.5f);

      for(int i=1;i<allBodys.Count; i++)
      {
        allBodys[i].FollowFront();
        yield return new WaitForSeconds(0.2f);
      }
    }
  }
 
 // Update is called once per frame
 void Update () {
 
    if(Input.GetKeyDown(KeyCode.A))
    {
      ((SnackHead)allBodys[0]).TurnLeft();
    }

    if (Input.GetKeyDown(KeyCode.D))
    {
      ((SnackHead)allBodys[0]).TurnRight();
    }
  }
}